Vestibular Neurectomy (aka Vestibular Nerve Section or VNS)

                This is an operation to divide the balance nerves and interrupt the connection between the inner ear and the brain.  90-95% of patients who undergo this operation will not have another spell of vertigo.  After the operation, dysequilibrium lasts until the brain learns to compensate and adapt to the lack of input from one inner ear.  The more patients use their balance system after surgery, the less time this adaptation process takes.

                There are three different approaches or ways to get to the vestibular nerves.  The middle fossa approach is the least commonly used and involves an incision above the ear followed by removal of bone over the brain.  The roof of the canal through which the balance nerves run is removed and the nerves are then divided.  Another approach is the retrolabyrinthine approach which involves incisions behind the ear similar to the endolymphatic shunt procedure.  The covering of the brain or dura is opened and spinal fluid is drained.  The balance nerves are then divided.  A third approach is the retrosigmoid (aka suboccipital) approach which involves an incision further behind the ear and removal of bone over the covering of the brain.  Spinal fluid is drained and the balance nerves are visualized and then divided.

                The fibers of the hearing and balance nerves run very closely together.  Infrequently some hearing loss may occur.  Depending on the level of hearing present, the hearing can be monitored during the course of the operation.  The facial nerve is the nerve that sends messages to the facial muscles to contract.  This nerve lies close to the hearing and balance nerves.  Just like hearing, the status of facial nerve functioning can also be monitored.

Retrosigmoid Approach

Retrolabyrinthine/Retrosigmoid Approach (RRVN)

RRVN Pictures

Slideshows of each approach to the VNS

Pros and cons of each approach to the VNS